643252479 has 4 divisors (see below), whose sum is σ = 857669976. Its totient is φ = 428834984.

The previous prime is 643252471. The next prime is 643252541. The reversal of 643252479 is 974252346.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 643252479 - 2³ = 643252471 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 643252479.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643252471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107208744 + ... + 107208749.

It is an arithmetic number, because the mean of its divisors is an integer number (214417494).

Almost surely, 2^643252479 is an apocalyptic number.

643252479 is a deficient number, since it is larger than the sum of its proper divisors (214417497).

643252479 is a wasteful number, since it uses less digits than its factorization.

643252479 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214417496.

The product of its digits is 362880, while the sum is 42.

The square root of 643252479 is about 25362.4225775063. The cubic root of 643252479 is about 863.2312544925.

The spelling of 643252479 in words is "six hundred forty-three million, two hundred fifty-two thousand, four hundred seventy-nine".